cgroup: add/update accessors which obtain subsys specific data from css

[deliverable/linux.git] / net / sched / cls_cgroup.c

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 5ee72a001df0b68c4bd25c70bfc75cf13dccc95f..af412ab2b477777f9348cc51c839681f72a42c24 100644 (file)
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -23,16 +23,19 @@
 #include <net/sock.h>
 #include <net/cls_cgroup.h>
 
+static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
+{
+       return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
+}
+
 static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
 {
-       return container_of(cgroup_css(cgrp, net_cls_subsys_id),
-                           struct cgroup_cls_state, css);
+       return css_cls_state(cgroup_css(cgrp, net_cls_subsys_id));
 }
 
 static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
 {
-       return container_of(task_css(p, net_cls_subsys_id),
-                           struct cgroup_cls_state, css);
+       return css_cls_state(task_css(p, net_cls_subsys_id));
 }
 
 static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp)